Never worry about organizing your music library again
â¹ Completely automatic and easy to use
â¹ Tags name, artist, album, album art, genre, year, and lyrics
â¹ Analyzes the track's unique fingerprint, so it can never be wrong
â¹ No existing track information necessary
â¹ Automatically corrects each track's information as it is added to iTunes

Very nice for fixing lyrics and backfilling year and genre. You may want to use CoverScout for better Cover quality, but this one has it all in one tool.
The price is for a year's subscription, but how often do you need to touch you entire collection?
Definitely worth the money - huge time saver

There were some songs that Pollux couldn't handle, but each time I ran it, it would get a couple more songs. So I suggest you run it once, then run it again on the ones that don't got through the first time, repeat. I have to guess this is because it takes a sample from a different piece of the song each time a song is examined.

"Over the last couple of days, Pollux has gotten an unanticipated high volume of traffic and downloads. Weâre very happy for the huge interest and success our app has received, but for the very same reason, the third-party services Pollux uses such as MusicDNS and Lyricwiki are no longer able to support Pollux for free. Thus, our current version (1.1.9) is broken.

"As we are just two college students not looking for any profit, we are unable to pay for the services Pollux depends on even with the very generous donations we have received. Weâre looking to resolve this issue and continue to bring you Pollux at the lowest cost we can manage. We apologize for Pollux not working until we can sort out this matter, and we thank you for your interest and patience.